Elevators are frequently installed in elevator shafts of buildings. In order to make optimum use of the space of a building, an elevator shaft should be as small as possible, and an elevator should utilize the elevator shaft as completely as possible. Consequently, elevator shafts are narrowly dimensioned so that optimum utilization of a building can be realized.
It can occur that an elevator shaft is dimensioned such that an elevator intended for it can find no space therein, or finds space only when it is arranged very exactly at a specific location in the elevator shaft. Consequently, following installation of an elevator an elevator shaft is frequently measured so that a fitter can be certain that the elevator really can be installed. If it is established in the measurement that the elevator shaft is too small, the elevator shaft can, if appropriate, be adapted, for example by smoothing shaft walls.
This measurement of the elevator shaft is conventionally accomplished with the aid of vertical ribbons. In this case, suspension means are fitted on a shaft ceiling at measured points so that the vertical ribbons hang at prescribed positions in the shaft space. However, this method requires a long time, since the fitter must undertake measurements, drilling and installation both in the shaft head and on the shaft floor.
Published patent application WO 2009/073010 describes a method and a device for measuring elevator shafts. In this case, a platform is moved in a longitudinal direction of the elevator shaft and distance sensors measure distances between this platform and the shaft walls. The platform is moved by a drive, and a position of the platform can be checked by light sensors. On the one hand, this solution supplies more accurate data for the dimensions of the elevator shaft, and removes the need to fit vertical ribbons on the shaft ceiling. However, there is the disadvantage here that it is necessary to install a drive and guidance system for the platform. In addition, this solution is expensive and complicated to produce.